This article or section contains information taken from the Warcraft strategy games and contains information relating to level editing or game mechanics.

For each race, The Frozen Throne adds several new units, buildings and upgrades, and one new hero per race.

The entirely new race "Naga" has also been added, and can be played in several Sentinel and Alliance missions, as well as in custom maps. A smaller race, the Draenei, have also been included, though they can only be played in an Alliance mission and custom maps.

The old siege engines of the humans, orcs and night elves have been renamed and remodeled, receiving new upgrades in the process (for example, Wyvern Riders were renamed Wind Riders, but the unit was otherwise unchanged).

Gold and lumber costs were recalculated, generally requiring more lumber for high-tech buildings and units; consequentially, the population limit was been increased from 90 to 100 to accommodate additional lumber-gathering workers.

The Frozen Throne reintroduced naval units into the game (they had been present in "Warcraft II", but were absent in "Reign of Chaos"), as well as amphibious creatures. Most aquatic mechanics were only available in the single-player campaign, but some creeps and the neutral Goblin Shipyard made island maps a viable template in melee matches (such maps became unpopular and were removed from the ladder selection).

New item mechanics were added, such as the neutral Marketplace, which sells a rotating inventory of items, player-built shops, and inventory upgrades for non-hero units.

The expansion and its subsequent patches made the addition of neutral Hero units. Neutral heroes can be used in melee maps via the Tavern, a neutral building to hire them. The tavern can also instantly revive any fallen hero, with an increased resource cost, and reduced health and mana of the revived hero. A nearby unit is needed to access the tavern.

Five new tilesets were added, each with its own set of creeps and critters. New doodads were included in old tilesets.*

The World Editor program was greatly expanded, allowing the user to do more custom work with regards to editing skills, doodads, and upgrades. Support for importing custom files into maps was added, as well as the creation of custom campaigns with campaign-specific data. An AI editor was also created for the expansion.

The Warden Maiev Shadowsong pursues the former prisoner Illidan Stormrage across Azeroth. Illidan has gained the allegiance of the naga, former night elves who adapted to underwater life, but they do not stop Maiev, who pursues Illidan from Kalimdor to the Tomb of Sargeras, then all the way to Lordaeron. During her chase, she asks the assistance of Malfurion Stormrage and Tyrande Whisperwind, but Maiev holds a grudge against Tyrande for her actions in releasing Illidan in the first place, culminating in her lying about Tyrande's death to Malfurion. Malfurion and Maiev successfully prevent Illidan from using the Eye of Sargeras, with the help of a blood elf, Kael'thas Sunstrider, but in the process, Maiev's treachery comes out, and the brothers Stormrage join forces to save their mutual beloved. Malfurion then pardons Illidan, though he does not revoke his exile, and Illidan departs...with Maiev still dogging at his heels.

The Alliance (the humans are not the main characters) Campaign follows the adventures of Prince Kael'thas, leader of the Blood Elves, a group of high elves that survived the invasion of Quel'Thalas by the Scourge. Originally helping the Alliance, the Blood Elves are imprisoned by a racist Human knight, Lord Garithos, and are eventually rescued by Lady Vashj and her Naga. Vashj then takes Kael'thas to the Outland, the remnants of the orc realm Draenor, to meet (and free) their master, Illidan. After fending off Maiev (again) and gaining the allegiance of the native Draenei, Illidan is able to conquer the Outland, where he hopes he will be safe from his failure to use the Eye of Sargeras to destroy the Frozen Throne. But his master, the demon lord Kil'jaeden, catches them nonetheless, and the episode ends with Illidan renewing his vow to destroy the Lich King.

The human forces in this campaign are very different than the ones used in the multiplayer game. Instead of the full Alliance, only the blood elven units are available, with the addition of a few new units and a blood elf hero added to the expansion pack. The draenei and the naga, with their lone heroes, are also eventually playable.

In the blighted lands of Lordaeron, now known as the Plaguelands, a civil war is taking place within the Scourge. The undead forces splinter into three major factions: Arthas and Kel'Thuzad, who are loyal to the Lich King; the Forsaken, led by the Banshee Queen Sylvanas Windrunner; and a third group still loyal to the Burning Legion, led by the Dreadlords (Nathrezim) who are unaware of the Legion's defeat on Mt. Hyjal. The campaign switches between Arthas' journey to Northrend to assist the Lich King, and Sylvanas' war against the Dreadlords for control of the Plaguelands. In the end, Sylvanas emerges as the nominal ruler of the Plaguelands, while Arthas travels to Northrend to defend the Lich King, meeting the subterranean Nerubian race, and eventually defeating Illidan in a one-on-one duel. (Contrary to popular belief, and the release of TBC, Illidan survived.) Arthas then ascends to the Frozen Throne and becomes one with the Lich King. What becomes of this unholy union is addressed in World of Warcraft.

The Bonus Campaign is a departure from the rest of the game and featured the three longest campaigns in the game. It has features more like an RPG similar to "Diablo", featuring a Beastmaster named Rexxar as he helps the orcs defend and develop their new home of Durotar from various enemies. The Bonus Campaign is probably meant as a bridge between the traditional "Warcraft" real-time strategy genre to the latest release of Blizzard, the MMORPG of "World of Warcraft". It was also created because the game's designers were having trouble getting the orcs involved in the main plot of "The Frozen Throne", and the RPG-style allowed Blizzard to show off many of the new features added in the World Editor, as an example of how custom maps can differ greatly from standard melee maps.

Initially, only one of the three acts was included in the game, allowing Blizzard to spend more time on the remaining two after release. Each act was expected to be released in a subsequent patch, but, due to delays in patch development, they were both finished and included in the first major patch in the expansion.

Warcraft III: The Frozen Throne was originally announced on January 22, 2003.[2] On February 14, 2003, Blizzard announced the first beta test for the game, which offered 10,000 players to sample the game.[3] On March 10, 2003, 10,000 more players were selected to participate in the beta test.[4] On May 29, 2003, Blizzard announced that the expansion set had "gone gold". And was released in July 1, 2003.

The Frozen Throne started at the version 1.07 of the game (by the time the game actually shipped patch 1.10 was downloadable), but there have been many patches after the expansion was released. Important changes, beside gameplay and World Editor changes, include the addition of some new maps in patches 1.17, 1.18, 1.19, 1.21 and 1.22; and the new neutral heroes Goblin Tinker, Goblin Alchemist and Firelord in patches 1.15 and 1.17. In patch 1.13 the Acts II and III of the Bonus campaign were added. The patch 1.21b allowed the game to be played without the official CD.

Due to the patch 1.23, many third-party programs were rendered unusable and it also disabled collided maps, which would make modified custom maps appear to be the same as the original. Another effect of the patch, which is not included in the release notes, is that custom maps with large filenames will not appear in the game. The limit is believed to be 20 characters, but this has not yet been tested.

The 1.23 patch included no actual changes to gameplay but rather dealt with security concerns relating to multiplayer hacks. The 1.24 patch and the subsequent and the 1.24a, 1.24b and 1.24c patches followed suit, also dealing with malicious code that could be contained in custom maps. Consequentially, many older maps using custom text rather than standard triggers may no longer work until updated. Hash Tables were added to the World Editor to compensate for some of the lost functionality.

There was a CD made to patch (possibly patch 1.17a[5] which includes patches 1.15 and 1.17?) the game with the new Goblin and Firelord neutral heroes. The CD has given much confusion that it is another expansion to Warcraft III: The Frozen Throne due to the CD having its own CD art and title named "Warcraft III: Goblin & Firelord" with words saying Expansion To Warcraft 3 Frozen Throne: Goblin & Firelord put in it but this CD was actually just the patch.